Installation of modular pin grounding. Grounding rod Modular grounding rod system diagram

Pin earthing

As you can see in the figure, arranging the ground loop on your own does not pose any particular difficulties. Today there are two main methods of grounding devices. The first, which has already become traditional, is when three or more metal pins are driven into the ground to a depth of 3 meters. And a more modern method, when one pin is driven into the ground to a depth of 30 m, i.e. to the maximum possible depth of the first aquifer.

1. Conventional grounding

Select a location on the site as close as possible to the lead-in cabinet (power panel). The optimal distance is considered to be no more than 10 m.

We dig a trench about 0.5 m wide and at least 0.8 m deep. The trench is dug in the shape of an equilateral triangle (3 x 3 x 3 m) with a branch to the power cabinet.

Then, at the corners of the triangle, we drill 3 wells with a depth of 3 meters and hammer in 3 corners of 3 meters each. If the soil in the area is soft, you can try to drive it in with a sledgehammer without drilling a well. The end of the corner should protrude slightly from the ground so that a metal strip can be welded to it.

To the three ground electrodes (corners) installed in the ground, we weld a steel strip along the perimeter. We lead one end of the strip from the ground loop to the power cabinet. Weld the strip to the cabinet body.

Before backfilling the trench, we check the resistance of the ground loop. To do this, you need to arm yourself with an Ohmmeter, for example: brands ES 0212 or any other similar. The resistance should not be higher than 10 ohms (usually 4-6 ohms). This is very small, for comparison - the resistance of the human body is on average 7000 ohms. If the loop resistance is higher than 10 ohms, drive another pin into the ground and weld it to the loop. Natural ground electrodes (metal fence posts, supports, etc.) will help to reduce the resistance of the grounding loop, if they are connected to the loop. Do not forget - all connections are made by welding.

A properly made ground loop will allow you to equip lightning protection in the future, i.e. lightning protection.

2. Single pin grounding

Modern household appliances and equipment require grounding. Only in this case will manufacturers maintain their guarantees. Inhabitants of apartments have to wait for the overhaul of networks, and house owners can do everything with their own hands. How to make grounding in a private house, what is the procedure and connection diagrams - read about all this here.

In general, ground loops can be in the form of a triangle, rectangle, oval, line or arc. The best option for a private house is a triangle, but others are also quite suitable.

Grounding in a private house - types of grounding loops

Triangle

Grounding in a private house or in the country is most often done with a contour in the form of an isosceles triangle. Why is that? Because with such a structure, on the minimum area, we get the maximum current dissipation area. The costs for the device of the grounding loop are minimal, and the parameters correspond to the nominal values.

The minimum distance between the pins in the triangle of the ground loop is their length, the maximum is twice the length. For example, if you drive the pins to a depth of 2.5 meters, then the distance between them should be 2.5-5.0 m. In this case, when measuring the resistance of the ground loop, get normal values.

During work, it is not always possible to make the triangle strictly isosceles - stones come across in the right place or other difficult-to-pass areas of soil. In this case, you can move the pins.

Linear ground loop

In some cases, it is easier to make a ground loop in the form of a semicircle or a chain of pins lined up in a line (if there is no free area of ​​suitable size). In this case, the distance between the pins is also equal to or greater than the length of the electrodes themselves.

With a linear circuit, a larger number of vertical electrodes are needed - so that the scattering area is sufficient

The disadvantage of this method is that a larger number of vertical electrodes are required to obtain the desired parameters. Since hammering them is still a pleasure, in the presence of meta, they try to make a triangular contour.

Ground loop materials

In order for the grounding of a private house to be effective, its resistance should not be more than 4 ohms. For this, it is necessary to ensure good contact of the ground electrodes with the ground. The problem is that grounding resistance can only be measured with a special device. This procedure is carried out when the system is put into operation. If the parameters are worse, the act is not signed. Therefore, when making the grounding of a private house or summer cottage with your own hands, try to strictly adhere to the technology.

Pin parameters and materials

Ground rods are usually made of ferrous metal. Most often, a bar with a cross section of 16 mm or more or a corner with parameters 50 * 50 * 5 mm (shelf 5 cm, metal thickness 5 mm) is used. Please note that the reinforcement cannot be used - its surface is hardened, which changes the distribution of currents, moreover, it quickly rusts and collapses in the ground. What you need is a bar, not an armature.

Another option for arid regions is thick-walled metal pipes. Their lower part is flattened in the form of a cone, holes are drilled in the lower third. For their installation, holes of the required length are drilled, since they cannot be hammered. When the soil dries out and the grounding parameters deteriorate, brine is poured into the pipes to restore the scattering ability of the soil.

The length of the grounding rods is 2.5-3 meters. This is sufficient for most regions. More specifically, there are two requirements:

Specific grounding parameters can be calculated, but geological survey results are required. If you have any, you can order a calculation in a specialized organization.

What to make metal bond and how to connect with pins

All pins of the contour are interconnected by a metal bond. It can be made from:

• copper wire with a cross section of less than 10 mm 2;
• aluminum wire with a cross section of at least 16 mm 2
• steel conductor with a cross section of at least 100 mm 2 (usually a strip of 25 * 5 mm).

Most often, the pins are connected to each other using a steel strip. It is welded to the corners or heads of the bar. It is very important that the quality of the weld be high - it depends on whether your grounding passes the test or not (whether it meets the requirements - the resistance is less than 4 ohms).

When using aluminum or copper wire, a bolt of a large section is welded to the pins, the wires are already attached to it. The wire can be screwed onto a bolt and pressed with a washer and nut, you can end the wire with a connector of a suitable size. The main task is the same - to ensure good contact. Therefore, do not forget to strip the bolt and wire to bare metal (you can handle it with sandpaper) and tighten it well - for good contact.

How to make grounding with your own hands

After all the materials have been purchased, you can proceed to the actual manufacture of the ground loop. To begin with, cut the metal into pieces. Their length should be more than the calculated one by about 20-30 cm - when the tops are hammered, the pins are bent, so you have to cut them off.

Sharpen the clogged edges of vertical electrodes - it will go faster

There is a way to reduce the resistance when hammering the electrodes - sharpen one end of the angle or pin at an angle of 30 °. This angle is optimal when driving into the ground. The second point is to weld a metal platform to the upper edge of the electrode, from above. Firstly, it is easier to hit it, and secondly, the metal is less deformed.

Work order

Regardless of the shape of the contour, it all starts with earthworks. A ditch needs to be dug. It is better to do it with beveled edges - this way it sprinkles less. The order of work is as follows:

Actually, that's all. Do-it-yourself grounding in a private house. It remains to connect it. To do this, you need to understand the grounding organization schemes.

Entering the ground loop into the house

The ground loop must be brought into the ground bus somehow. This can be done using a steel strip 24 * 4 mm, copper wire with a cross section of 10 mm2, aluminum wire with a cross section of 16 mm2.

In the case of using wires, it is better to look for them in isolation. Then a bolt is welded to the contour, the end of the conductor is put on a sleeve with a contact pad (round). A nut is screwed onto the bolt, a washer is screwed onto it, then a wire, on top is another washer and all this is tightened with a nut (picture on the right).

How to bring "earth" into the house

When using a steel strip, there are two ways out - to bring a bus or a wire into the house. I really don't want to pull a steel tire 24 * 4 mm in size - it looks unaesthetic. If there is, you can use the same bolted connection to run a copper bus. It needs a much smaller size, it looks better (photo on the left).

You can also make a transition from a metal bus to a copper wire (section 10 mm2). In this case, two bolts are welded to the bus at a distance of several centimeters from each other (5-10 cm). The copper wire is twisted around both bolts, pressing them with a washer and nut to the metal (tighten as best as possible). This method is the most economical and convenient. It does not require as much money as using only copper / aluminum wire, it is easier to run it through the wall than a bus (even copper).

Grounding schemes: which one is better to do

At the moment, in the private sector, only two grounding schemes are used - TN-C-S and TT. For the most part, a two-core (220 V) or four-core (380 V) cable (TN-C system) is suitable for the house. With such wiring, in addition to the phase (phase) wire, a protective PEN conductor comes, in which zero and ground are combined. At the moment, this method does not provide adequate protection against electric shock, therefore it is recommended to replace the old two-wire wiring with three-wire (220 V) or five-wire (380 V).

In order to obtain a normal three- or five-wire wiring, it is necessary to separate this conductor into PE and neutral N (in this case, an individual ground loop is required). This is done in an introductory cabinet on the facade of the house or in an accounting and distribution cabinet inside the house, but always before the counter. Depending on the separation method, either a TN-C-S system or a TT system is obtained.

Device in a private house of the TN-C-S grounding system

When using this circuit, it is very important to make a good individual ground loop. Please note that with the TN-C-S system, the installation of RCDs and difavtomats is required to protect against electric shock. Without them, there is no question of any protection.

Also, to ensure protection, it is required to connect all systems that are made of conductive materials to the earth bus with separate wires (inseparable) - heating, water supply, reinforcement cage of the foundation, sewage, gas pipeline (if they are made of metal pipes). Therefore, the grounding bus must be taken "with a margin".

To separate the PEN conductor and create a ground in a private house TN-CS, three buses are needed: on a metal base - this will be the PE (ground) bus, and on a dielectric base - this will be the N (neutral) bus, and a small splitter bus for four " seats.

The metal "earth" bus must be attached to the metal body of the cabinet so that there is good electrical contact. To do this, in the attachment points, under the bolts, the paint is cleaned from the body to pure metal. The zero bus - on a dielectric base - is best mounted on a DIN rail. This installation method fulfills the main requirement - after separation, the PE and N buses should not intersect anywhere (should not have contact).

Grounding in a private house - transition from the TN-C system to the TN-C-S

• The PEN conductor coming from the line is fed to the splitter bus.
• We connect the wire from the ground loop to the same bus.
• From one socket with a copper wire with a cross section of 10 mm 2 we put a jumper on the ground bus;
• From the last free socket we put a jumper on the zero bus or the neutral bus (also copper wire 10 mm 2).

Now that's it - grounding in a private house is made according to the TN-C-S scheme. Further, to connect consumers, we take the phase from the input cable, zero - from the N bus, ground - from the PE bus. We make sure that the ground and zero do not intersect anywhere.

TT earthing

Converting a TN-C to TT circuit is generally simple. Two wires come from the post. The phase is still used as a phase, and the protective PEN-conductor is attached to the "zero" bus and further is considered to be zero. A conductor from the made circuit is directly fed to the ground bus.

Do-it-yourself grounding in a private house - TT scheme

The disadvantage of this system is that it protects only those equipment, which is provided for the use of "earth" wire. If there are still household appliances made in a two-wire circuit, they may be energized. Even if the housings are grounded with separate conductors, in case of problems, the voltage may remain at "zero" (the circuit breaker will break the phase). Therefore, of these two schemes, TN-C-S is preferred as more reliable.

In this article, I will introduce a newer and more advanced grounding system - the modular pin system. You will familiarize yourself with the conditions and methods of installing such a grounding center and the advantages of such a system. I also want to tell you how and with the help of what and how, without involving a special measuring laboratory, to control the resistance of the grounding loop. I will tell you what to do if, over time, the resistance of the ground loop has changed upward.

Modular stud grounding system

This system is formed by vertical steel rods and couplings. See fig. 1 and fig. 2. The rods, each 1.5 m long, are coated with a layer of copper. Couplings made of brass are designed to connect rods to each other.

Rice. 1 Ground rod 58-11 "UNC

• Stem length: 1500 mm.
• Stem diameter: 14.2 mm.
• Thread: 5/8 ”-11UNC on both sides, copper-plated.
• Thread length: 30mm.
• Weight, 1.85 kg.

Rice. 2 Coupling MC-58-11

• Brass L-63 (production of bronze is allowed).
• Length 70mm.
• Diameter 22 mm.
• Internal thread: 5/8 ”-11UNC.
• Thread length 60 mm.
• Weight 0.114 kg.

The set of the device includes a brass clamp required to connect the vertical and horizontal components of the ground loop. I will call the vertical component a steel rod, the horizontal one - a steel strip or copper wire from the distribution board to the grounding office. See fig. 3. The equipment includes two types of steel lugs screwed onto a rod vertically driven into the ground. Each tip is used for a different type of soil: hard soil or normal soil. See fig. 4.

Rice. 3. Clamps universal MS-58-11

Rice. 4. Tip 58-11 "UNC

• Tip length - 42 mm.
• The diameter of the steel tip is 20 mm.
• Thread: female 5/8 ”-11UNC.
• Thread length: 20mm.
• Weight 0.045 kg.

A landing pad is attached to the main equipment of the system. 5 and special attachment fig. 6. They are needed for the application and transmission of vibratory hammer forces.

Rice. 5. Landing pad 5/8 "-11UNC

• Length 53 mm.
• Diameter 23.6 mm.
• External thread 5/8 ”-11UNC.
• Thread length 35 mm.
• Weight 0.110 kg.

Rice. 6. Impact nozzle НУ

• Length 265 mm.
• The diameter of the main part is 18 mm.
• The diameter of the working part is 11.7 mm.
• The length of the working part is 14.5 mm.

The main equipment is supplied with an electrically conductive anti-corrosion liquid anti-corrosion paste fig. 7 and protective tape fig. 8 for clamping the vertical and horizontal components of the system.

Rice. 7. Anticorrosive conductive grease

Electrically conductive graphite grease is used to provide a continuous electrical circuit for the vertical grounding electrode. It is a multigrade electrically conductive lubricant. The lubricant is applied to the threaded connections of all mounting structures. It has good adhesion to the surface and its parameters do not change over time when the joint is heated with a current of 1.2 kA to a temperature of + 40C?. It protects against corrosion and maintains a constant electrical resistance under operating conditions. When using a lubricant, it is possible to reduce the joint resistance by 9-11%. When heated, the lubricant does not flow, and the resistance of the stacks decreases by 55-60% due to the good filling of the unevenness of the joint.

Rice. 8. Anticorrosive tape

The tape is used to protect underground and aboveground pipes, rods, valves, fittings, metal fittings from corrosion. It has good plasticity even when exposed to temperatures. Resistant to acids, alkalis, salts and microorganisms, does not allow water, steam and gases to pass through.

For the convenience of installing this system, you must have a vibratory hammer in use fig. 9, and to control the resistance to spreading of the main ground electrodes - a resistance measuring device Fig. 10. I recommend using a vibrating hammer such as BOSCH GSH 11 E Professional f. Bosch or MH 1202 E Makita f. Makita. As a device for measuring grounding resistance, I advise you to take a device of the type F4103-M1

Rice. 9. Vibrating hammer

Rice. 10 Ground resistance meter F4103-M1

Installation work

Installing the Resistance Meter

We will install the resistance measuring device near the place where we are going to carry out the installation of the ground loop. For this, we define a hole 200 x 200 x 200 mm, dug at a distance of 1.5 m from the exit of the horizontal component of the ground loop from the wall of the house. It can be a steel strip or copper wire. We place the measuring electrodes necessary for making measurements at a distance of 25 and 10 m on opposite sides of the device and drive them into the ground. Then we connect the electrodes to the F4103-M1 device.

See Figure 11 for the installation diagram of the measuring electrodes:

Fig. 11. Wiring diagram for measuring electrodes

Installing the first vertical modular pin

We proceed to the installation of the grounding itself. We screw the tip onto one end of the rod. All threads on steel equipment, as the company guarantees to us, are applied after the rod and tips are coated with copper. Before making the connection, we will treat the tip with an anti-corrosion conductive paste. On the other end of the rod we screw a connecting sleeve, which we then also fill with anti-corrosion conductive paste. We wind the landing head from above to apply the forces of the vibratory hammer. The assembled rod, tip down, as far as possible with the effort of the hands, stick into the prepared hole, into the ground. Then we use a vibratory hammer. He works for us from a 220V network. We attach the percussion device of the vibrating hammer to the rod platform, turn on the hammer and hold this alignment, literally in 20 seconds, sink the rod to its full length into the ground, leaving 20 cm above the bottom of the pit in order to connect it to another rod.

Measuring Intermediate Spreading Resistance

We remove the landing pad from the pin and measure the spreading resistance. We connect the F4103-M1 device with the installed stem. The resistance at a depth of 1.5 m was, for example, 485 ohms.

To achieve a given spreading resistance, the modular pin system offers to deepen the vertical pins, building up the ground sections, one on top of the other. We carry out everything according to the recommendations of the instructions.

Mounting Subsequent Vertical Modular Pins

We process the connecting sleeve with paste and screw the second copper rod into it, screw the second connecting sleeve onto the rod, treating it with anti-corrosion paste, and again attach the landing head. We apply a vibrating hammer to the device and repeat the previous process. We control the resistance to spreading.

We will carry out the process of growing the rods until the spreading resistance reaches a value of less than 4 ohms. When performing this process, we will not forget to treat the connections of each ground section with a protective anti-corrosion paste. Finally, after installing the seventh rod, we obtained a spreading resistance of, say, 3.35 Ohm at a depth of 10.5 m.

Installation of a horizontal earthing switch in a modular pin system

Now we proceed with the installation of the connection between the vertical grounding conductor and the horizontal grounding conductor. A brass clamp is used to connect the steel strip or cable to the rod. One part of the clamp is adapted for connecting a pin, the other half is a seat for a steel strip or cable. On the end of the rod protruding from the ground, we fasten the brass clamp with bolted connections. We bring the horizontal component of the grounding to the same terminal: a steel strip or a copper cable and also fasten it with bolted connections. The cable (strip) and the pin are separated by a special dividing plate, which is necessary to prevent a seat of bimetallic corrosion when dissimilar metals come into contact. After connecting the strip or cable, we process the bolted joints with a special tape of the PREMTAPE type. It provides additional protection against corrosion of the contact of the vertical and horizontal components of the ground. See fig. 12

Rice. 12. Deep modular pin earthing system

The ground loop, made using a modular pin system, can be configured as a single-point or multi-point ground loop, which will achieve the required resistance of the ground electrodes.

Advantages of a modular grounding rod system

Having drawn the graph in Fig. 13, showing the dependence of the spreading resistance on the depth of the grounding rod, we summarize the work done. The earthing system installed in less than an hour made it possible to achieve a spreading resistance of less than 4 ohms.

Fig. 13 Dynamics of changes in grounding resistance from the depth of the rod

Let's consider what conditions the installed system required? To complete the ground loop using a modular pin method, it was required, firstly, a vibratory hammer to save the installer from efforts; secondly, a measuring device and, thirdly, a second assembler-assistant to support the rod during operation of the vibratory hammer.

We establish, what are the advantages of the modular pin ground loop system in comparison with the generally recognized and commonly used classic ground loop.

• The modular pin system took up an area of ​​less than one square meter, that is, the limited installation area is not a hindrance to it.
• There is no exhausting excavation work, everything is done by one vibratory hammer.
• No welding required, all connections in the modular pin system are made with couplers.
• Long service life, more than 30 years, thanks to anti-corrosion coatings and lubricants, that is, high resistance to soil and electrolytic corrosion.
• The use of a deep modular pin system makes it possible to not depend on the characteristics of the soil.
• Simple construction in terms of the device and accessible to everyone in terms of installation, even one person can handle.

Of course, the question will be about the cost of such a system. The cost of equipment for a ground loop device using a modular pin system will be approximately 500USD. The cost of the installation of the system will be 120 USD. The classic grounding system by materials will cost 100 USD and 120 USD are estimated for installation work. But I want to say that although the classic system is cheaper, all seven of the benefits listed above justify the cost of installing a modular grounding rod system.

After completing the arrangement of the ground loop, it is necessary to draw up the following documents: measurement protocol; hidden works act; grounding passport with a diagram. All this should be kept by the owner.

Fig. 14 grounding certificate

Conclusion

I have shared with you my experience in choosing a grounding method. Now you know how to quickly and at a high technical level to protect yourself and your loved ones from electric shock, and your house from fire.

Attention! The prices in the article are outdated.

ZANDZ modular grounding
(ave. Russia) is intended for the installation of grounding devices (earthing switches) at residential buildings (house, summer cottage), at telecommunications and energy facilities of mobile and fixed-line operators, at industrial enterprises.

Such an earthing switch is a prefabricated structure consisting of steel rods, 1.5 meters long, connected together, covered with a layer of copper.

Advantages of modular grounding

The advantage of the modular pin design:

• ease of mounting the electrode to a depth of 30 meters, without the use of specialized equipment and tools. All operations are carried out by 1 person. The great depth allows very effective grounding.


• the minimum area occupied by the ground electrode allows you to mount such grounding in the basements of buildings, or in the vicinity of the walls of the house in the form of just one point. The compactness minimizes the necessary excavation work.


• all parts are mated without welding *

The superiority of the industrial production of elements is:

• excellent resistance of all parts to corrosion, which is reflected in the service life of the earthing switch up to 100 years.


• full resistance of the copper coating of the pins to mechanical damage (for example, bending and peeling) during installation, which allows installation in soils with the presence of gravel or small debris
  (due to the use of the technology of electrolytic deposition of copper on steel).

* Connection of elements of grounding devices NOT made of ferrous metals is permitted by technical circular 11/2006 of the RosElektroMontazh association (link to document)

Grounding kits

For the construction of grounding devices with the necessary characteristics (for example, to achieve the required grounding resistance), various ready-made modular grounding kits from ZANDZ (etc. Russia) are used, which contain everything you need to mount the grounding electrode.

All components are easy to interface with each other.

Five types of ready-made kits are produced, differing in the total length of the pins, the main purpose and the complete set:

Traditional ground electrode
(set ZZ-000-045)

A large number of vertical electrodes installed at a shallow depth

Special earthing switch
(sets ZZ-000-424
and ZZ-000-636)

Installation of grounding for container objects

Equipment

Individual complete set

Components

The brass sleeve is designed to connect the pins to each other. It is made in such a way that the pins are in contact with each other in the very center of the clutch and the driving energy necessary for burying the pins into the soil is not transferred to the clutch. Thus, there is no "dispersion" of the shock impulse and also removes the mechanical load from the coupling.

The pointed steel tip makes it easy to penetrate the pins into hard ground.

Profiled stainless steel clamp with M10 bolts. Allows you to connect the copper-plated pin to the grounding conductor - a round wire or a strip (up to 40 mm wide).

It is possible to safely use a steel and galvanized conductor - for this, there is a gasket inside the clamp that prevents the formation of an electrochemical bond between steel / zinc and copper.

To prevent self-loosening of bolt-nut threaded connections, spring washers (Grover washers / Grover washers) are used, installed between the clamping surface and the nut.

It is used to reduce the electrical resistance between the pins and the sleeve, as well as to additionally protect the ends of the pins (in the sleeve) from corrosion. Lubricant is also used for the pilot head, making it easier to remove after the next pin is buried. During installation, grease is applied to the threads of the parts.

The tape is used to protect the connection of the pin with the grounding conductor from soil and electrochemical corrosion by completely displacing water (moisture) from the connection, without which the corrosion process is impossible. At the same time, the tape does not lose its physical and mechanical properties for many years.

Made of non-woven synthetic fibrous material impregnated and coated with a neutral composition based on saturated petroleum hydrocarbon (petrolatum) and an inert silicon-containing filler. Remains pliable when exposed to a wide range of temperatures. Does not harden or crack. Highly resistant to inorganic acids, alkalis, salts and microorganisms, highly hermetic against water, steam and gas.

Only the conductor clamps are protected with this tape.

A steel nozzle with a heated striker transmits the force of the jackhammer to the guide head (to the pins to be mounted). Adapted to work with demolition hammers with a seat SDS-Max.

Additional elements

Grounding conductor (PV-1 25 mm²)

Copper single-core, stranded and stranded conductor with cross-section from 4 to 185 mm² in PVC insulation is used to connect the ground electrode system to the object (GZSH in the shield).

The conductor is supplied by the meter and in ready-made bays of 3/5/10 meters
(ZZ-500-103 / ZZ-500-105 / ZZ-500-110), crimped at one end with a lug with a hole for a D8 bolt for attaching to the GZSh in the shield.